Fix visibility notification event reporting
Fix visibility notification event reporting

We were checking the event mask for GDK_VISIBILITY_NOTIFY,
not GDK_VISIBILITY_NOTIFY_MASK, which was clearly a typo.

Distrotech/gtk2,chergert/gtk,Sidnioulz/SandboxGtk,davidgumberg/gtk,Lyude/gtk-,Adamovskiy/gtk,davidt/gtk,alexlarsson/gtk,ahodesuka/gtk,jadahl/gtk,Adamovskiy/gtk,davidgumberg/gtk,bratsche/gtk-,msteinert/gtk,jessevdk/gtk,Lyude/gtk-,ahodesuka/gtk,ahodesuka/gtk,jadahl/gtk,ahodesuka/gtk,Lyude/gtk-,ebassi/gtk,davidgumberg/gtk,davidgumberg/gtk,jigpu/gtk,ebassi/gtk,jessevdk/gtk,alexlarsson/gtk,Distrotech/gtk2,ebassi/gtk,msteinert/gtk,grubersjoe/adwaita,ahodesuka/gtk,jigpu/gtk,chergert/gtk,jigpu/gtk,jigpu/gtk,alexlarsson/gtk,Sidnioulz/SandboxGtk,Distrotech/gtk2,chergert/gtk,davidt/gtk,jigpu/gtk,msteinert/gtk,davidt/gtk,davidgumberg/gtk,Adamovskiy/gtk,grubersjoe/adwaita,ahodesuka/gtk,ahodesuka/gtk,jessevdk/gtk,bratsche/gtk-,bratsche/gtk-,grubersjoe/adwaita,grubersjoe/adwaita,msteinert/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,bratsche/gtk-,davidgumberg/gtk,jessevdk/gtk,chergert/gtk,jadahl/gtk,Lyude/gtk-,davidgumberg/gtk,grubersjoe/adwaita,Lyude/gtk-,jigpu/gtk,jadahl/gtk,chergert/gtk,jigpu/gtk,Distrotech/gtk2,Lyude/gtk-,davidt/gtk,ebassi/gtk,Sidnioulz/SandboxGtk,davidt/gtk,jadahl/gtk,Sidnioulz/SandboxGtk,grubersjoe/adwaita,Distrotech/gtk2,Distrotech/gtk2,Lyude/gtk-,Sidnioulz/SandboxGtk,ebassi/gtk,jadahl/gtk,jessevdk/gtk,davidt/gtk,jessevdk/gtk,bratsche/gtk-,alexlarsson/gtk,chergert/gtk,alexlarsson/gtk,chergert/gtk,jadahl/gtk,grubersjoe/adwaita,alexlarsson/gtk,Adamovskiy/gtk,Adamovskiy/gtk,Adamovskiy/gtk,davidgumberg/gtk,msteinert/gtk,jessevdk/gtk,Adamovskiy/gtk,chergert/gtk,jadahl/gtk,jigpu/gtk,ebassi/gtk,Adamovskiy/gtk,bratsche/gtk-,alexlarsson/gtk,grubersjoe/adwaita,alexlarsson/gtk,msteinert/gtk,Lyude/gtk-